External Hardrive Question

[seadog]

Hope I am posting in the right forum. I have a question about a recently installed Maxtor One Touch 3 mini external harddrive. Seems to be working fine but when I put PC in standby mode external drive makes a clicking sound for a few seconds then goes quiet. Then starts clicking again off & on while PC remains in standby. Can someone tell me if this is normal? Couldn't find any answers on manufacturers site. Thanks in advance for your time.

[Ice_Czar]

interspersed throughout the platter(s) on a HDD are what are called servo bursts (http://www.lostcircuits.com/hdd/hdd2/3.shtml), think of them as GPS markers, the density (http://www.storagereview.com/map/lm.cgi/areal_density) of the data is so high that the head (http://www.storagereview.com/guide2000/ref/hdd/op/heads/index.html) needs to be super accurately placed in order to read or write data. A "click" is the drive recalibrating its position after a seek and a miss, it does this normally all the time due to small thermal changes that effect the relative positions of things, when there is a true error, and Id gather in this instance as power is cut\interrupted.

Many drives also have safety mechanisms in the event of power loss that parks the head which floats on a boundary of air 2 microns above a spinning platter's surface whenever the platter starts to slow down, avoiding the old need to have a "landing zone", now they are locked "up" away from the surface. After the drive platter spins up to speed again the drive will lower the head to again float on the air and need to recalibrate its position (normally a full seek arc from inner to outer track and back to where it needs to be to fulfill a read\write request

between the two its very likely just the normal noises your hearing.

when you get the "click of death" its the drive in a constant seek and miss cycle
seek miss recalibrate seek miss recalibrate seek miss ect
the occasional click is normal, but a trend of more clicks isnt good,
since a changing power state is involved here Id say its likely normal

I would make sure nothing is asking the drive for information you dont need (indexing service for instance, unimportant incremental logs getting written) you can check file access with filemon (http://www.microsoft.com/technet/sysinternals/FileAndDisk/Filemon.mspx) there is also a registry key that controls the power state

the normal minimum setting is 3 minutes, changing the following registry key to a 1, you can select 1 minute.

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Controls Folder\PowerCfg]

"DiskSpinDownMin"="1"

5 or 10 minutes is common for normal use, as the constant stopping and starting could be cause for a bit of wear and tear but power states are a personal choice and largely dependent on your unique access pattern

[seadog]

Ice_Czar...thanks for the rapid & in depth response. If I understand correctly( and there is every possibility that I don't given my limited PC knowledge) there must still be HD activity on my PC even when in standby mode & that is what causes the intermitent clicking on the external drive & that is normal.

[pugmug]

Wow,nice response Ice.One question if I may ask?Why would you leave an external h/d on all the time?I just use the power switch of the external enclouser to turn mine on when needed and off when not.

[Ice_Czar]

seadog
Id consider a click when your not actively trying to access data on the drive something worth hunting down and eliminating. The first culprit being the indexing service
(RClick the drive\partition in windows explorer > properties > uncheck "Allow indexing service to index this disk for fast file searching)
alternately disable indexing service altogether (start > run > (type) > services.msc > DClick indexing service > Disabled) but as mentioned other aps might be reading and writing to the drive, AV scanning, ect which is where filemon comes in.

pugmug
the only possibility I can think of is the potential wear introduced through power on and off cycles, first there is thermal cycling as a potential for accelerating wear, then there is the possibility of surge\sag in the power (overshoots\undershoots to the baseline voltage). Really depends on the power delivery chain

the ideal state for a HDD is constant temperature and power state as far as the circuit board portion is concerned (all the semiconductors) and "off" as far as all the mechanical is concerned.

Unlike in a data center where access is often constant, the environment controlled and the power super stable with failover precautions which is a very "stable" environment with predictable wear factors, a single user environment with a considerable number of off on cycles (both power and thermal) are the norm and have been addressed by the manufacturer to some degree, as have the heightened potential for operational impacts you also get in externals.

But all in all its best to still treat a HDD like its loaded with nitro and give it a home where its as stable as possible. Either adopting a strategy that its "down" most of the time or "up" most of the time.

I cant specifically address what the power quality and wear potential is for a given external enclosure\auxillary linear power supply. (the vast gulf between theoretical knowledge of reliability factors and how they are determined and the real world results of precautions implemented by manufacturers, see this thread (http://www.wilderssecurity.com/showthread.php?t=165780))

[pugmug]

Agree Ice.I use a very good UPS to keep clean voltage and only turn on or off an external h/d as needed to lower the ware and tear on that drive.It is for backup so not needed all the time.

[seadog]

Because of limited data input I only need to backup every 2 weeks or so. I think the best solution for me is as pugmug suggested.....on when needed off when not. Thanks for the help.

[Ice_Czar]

off and safely out of the way of "accidents" ;) :thumb:

HDDs are a lot more robust these days,
but treating them like unstable explosives devices still pays dividends

[HandsOff]

-{ Quote: "Then starts clicking again off & on while PC remains in standby. Can someone tell me if this is normal? " }-


It would be helpful to know the duration of these clicks, and periods of silence. If it is enough to be noticed I would suspect the worse. When you say one touch 3 "mini" do you mean a pocket sized drive (laptop drive)? Is it a combo drive or USB 2.0 only? Did you reformat the drive before using it (hopefully yes - I think they are formated FAT-32 by default).

There is a setting to either Optimize the Drives Performance, or, Optimize the Drive for quick removal (don't have to use the safely remove hardware icon before powering off the drive. It has to do with enabling write-caching. If you do not use the Safely Remove Hardware icon when you turn off your computer (Or drive) you should not have write caching enabled.

1-check that setting
2-agree with Iceman, check that the indexing service is not enabled
3-run chkdsk /f on the drive <----Important!
4-I would disable any kind of hibernating settings that can effect the drive.
5-I would not defragment this drive either automatically, or manually while it if it is only for storing backup files.
6-If you did not format it NTFS then you need to do it.

That's a start...

-HandsOff

[Note sure of your familiarity level with computers, so I wanted to say all of the above steps are really easy! if you don't know the steps, I or someone else here can tell you. I'd say you could almost safely ignore everything except #3!]

[seadog]

Thank you HandsOff...I have spent alot of time on the Maxtor (now Seagate) site & will try to answer your questions based on what I think I understand from what I have read.The device is a Maxtor One Touch lll mini edition for backup & storage. It is USB 2.0 only. Didn't see any options to reformat & don't know if it's FAT-32 or NTFS. It appears the only way to properly remove device is to use the safely remove hardware icon. Yes the indexing service is disabled & has been for years. I have not run chkdsk as yet as it is a brand new device & I wasn't aware that needed to be done. It does have its own self test built in which reports it is operating OK. To test it myself I have deleted some old files & restored them from the restore function of the device so it seems to be doing what it is supposed to do. My concern arose from the fact that I leave my PC in standby mode for hours at a time & I noticed the device would occasionally start ticking for 5 or 6 seconds then stop. It would repeat this pattern off & on. The reason I was concerned is that I thought that when in standby mode there would be no hard drive activity & therefore no reason for any ticking. If I am mistaken in that regard please advise...My understanding is based on my freely admitted limited knowledge in dealing with hardware ......I do a little better with software. I'm just an old dog trying to learn some new tricks. Sometimes that is not so easy. Thanks again for all your help.

[Ice_Czar]

running CHKDSK on a regular basis is not a bad idea
though automatically fixing errors (/f switch) may preclude the ability to easily recover data in the event errors are located in the filesystem, the filesystem normally fixes itself but on occasion when there is serious damage can orphan files and break otherwise functional OS installs. While its more time consuming to run CHKDSK without the /f switch it is the more cautious approach. This will give you an idea of what its actually doing.

An Explanation of CHKDSK and the New /C and /I Switches (http://support.microsoft.com/?kbid=187941)

-{ Quote: "<MORE

"To understand when it might be appropriate to use these switches (/C and /I) , it is important to have a basic understanding of some of the internal NTFS data structures, the kinds of corruption that can take place, what actions CHKDSK takes when it verifies a volume, and what the potential consequences are in circumventing CHKDSK's usual verification steps.

CHKDSK's activity is split into three major "passes" during which it examines all the "metadata" on the volume and an optional fourth pass. Metadata is "data about data." It is the file system overhead, so to speak, that is used to keep track of everything about all of the files on the volume. Metadata tells what allocation units make up the data for a given file, what allocation units are free, what allocation units contain bad sectors, and so on. The "contents" of a file, on the other hand, is termed "user data." NTFS protects its metadata through the use of a transaction log. User data is not so protected.

During its first pass, CHKDSK displays a message on the screen saying that it is verifying files and counts from 0 to 100 percent complete. During this phase, CHKDSK examines each file record segment (FRS) in the volume's master file table (MFT). Every file and directory on an NTFS volume is uniquely identified by a specific FRS in the MFT and the percent complete that CHKDSK displays during this phase is the percent of the MFT that has been verified. During this pass, CHKDSK examines each FRS for internal consistency and builds two bitmaps, one representing what FRSs are in use, and the other representing what clusters on the volume are in use. At the end of this phase, CHKDSK knows what space is in use and what space is available both within the MFT and on the volume as a whole. NTFS keeps track of this information in bitmaps of its own that are stored on the disk allowing CHKDSK to compare its results with NTFS's stored bitmaps. If there are discrepancies, they are noted in CHKDSK's output. For example, if an FRS that had been in use is found to be corrupted, the disk clusters formerly associated with that FRS will end up being marked as available in CHKDSK's bitmap, but will be marked as being "in use" according to NTFS's bitmap.

During its second pass, CHKDSK displays a message on the screen saying that it is verifying indexes and counts from 0 to 100 percent complete a second time. During this phase, CHKDSK examines each of the indexes on the volume. Indexes are essentially NTFS directories and the percent complete that CHKDSK displays during this phase is the percent of the total number of directories on the volume that have to be checked. During this pass, CHKDSK examines each directory on the volume for internal consistency and also verifies that every file and directory represented by an FRS in the MFT is referenced by at least one directory. It also confirms that every file or subdirectory referenced in each directory actually exists as a valid FRS in the MFT and checks for circular directory references. Finally, it confirms that the various time stamps and file size information associated with files are all up-to-date in the directory listings for those files. At the end of this phase, CHKDSK has ensured that there are no "orphaned" files and that all the directory listings are for legitimate files. An orphaned file is one for which a legitimate FRS exists, but which is not listed in any directory. When an orphaned file is found, it can often be restored to its rightful directory, provided that directory is still around. If the directory that should hold the file no longer exists, CHKDSK will create a directory in the root directory and place the file there. If directory listings are found that reference FRSs that are no longer in use or that are in use but do not correspond to the file listed in the directory, the directory entry is simply removed.

During its third pass, CHKDSK displays a message on the screen saying that it is verifying security descriptors and counts from 0 to 100 percent complete a third time. During this phase, CHKDSK examines each of the security descriptors associated with each of the files and directories on the volume. Security descriptors contain information regarding the owner of the file or directory, NTFS permission for the file or directory, and auditing information for the file or directory. The percent complete in this case is the percent of the number of files and directories on the volume. CHKDSK verifies that each security descriptor structure is well formed and internally consistent. It does not verify that the listed users or groups actually exist or that the permissions granted are in any way appropriate.

The fourth pass of CHKDSK is only invoked if the /R switch is used. /R is used to locate bad sectors in the volume's free space. When /R is used, CHKDSK attempts to read every sector on the volume to confirm that the sector is usable. Sectors associated with metadata are read during the natural course of running CHKDSK even when /R is not used. Sectors associated with user data are read during earlier phases of CHKDSK provided /R is specified. When an unreadable sector is located, NTFS will add the cluster containing that sector to its list of bad clusters and, if the cluster was in use, allocate a new cluster to do the job of the old. If a fault tolerant disk driver is being used, data is recovered and written to the newly allocated cluster. Otherwise, the new cluster is filled with a pattern of 0xFF bytes. When NTFS encounters unreadable sectors during the course of normal operation, it will also remap them in the same way. Thus, the /R switch is usually not essential, but it can be used as a convenient mechanism for scanning the entire volume if a disk is suspected of having bad sectors.

The preceding paragraphs give only the broadest outline of what CHKDSK is actually doing to verify the integrity of an NTFS volume. There are many specific checks made during each pass and several quick checks between passes that have not been mentioned. Instead, this is simply an outline to the more important facets of CHKDSK activity as a basis for the following discussion regarding the time required to run CHKDSK and the impact of the new switches provided in SP4"

MORE> " }-

Description of Enhanced Chkdsk, Autochk, and Chkntfs Tools in Windows 2000 (http://support.microsoft.com/default.aspx?scid=http://support.microsoft.com:80/support/kb/articles/Q218/4/61.ASP&NoWebContent=1)
CHKDSK XP syntax & switches (http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/chkdsk.mspx?mfr=true)

its probably worthwhile to find the time to read this as well ;)
http://www.ntfs.com/ (specifically the NTFS basics (http://www.ntfs.com/ntfs_basics.htm))

[DVD+R]

Erm, doesnt the external drive power down with the system :blink: I have a Notebook external Hard Drive, and it powers down or off with the system 8)

[seadog]

Ice Czar...I have read the info on the links you posted & found it very informative. Thank you.

DVD+R....I believe we are thinking along the same line on this. I have now discovered that even when PC is in standby this particular external drive stays powered up for a preset period of time which is why it was still active & intermittently clicking. After the preset time passes it too powers down & the intermittent clicking stops. When the PC comes out of standby the external drive also reactivates.This time was preset at 1 hour by default. I have reset the time to the minimum & all seems well.

I would like to thank all for your help & suggestions.